Neuro 2 final Flashcards
Where are globular bushy cells located?
posterior ventral nucleus
Where are spherical bushy cells located?
anterior nucleus
What do bushy cells relay?
frequency
What is the ratio of bushy cells to hair cells in the cochlea?
1:1
Where are octopus cells located?
dorsal/ventral cochlear nuclei
What do octopus cells detect?
interval between frequencies
SPECIFICALLY ONSET AND DURATION
Where do octopus cells send axons?
anterior nucleus of the LL
Multipolar cells send information about?
intensity
the superior olive detects what?
localization of sound and intensity differences from side to side
time lag is
interaural time
localizing sound in space; comparing one side to the other
interaural time is the responsibility of what structure?
SO
The medial SO has what cells?
bipolar
the medial SO detects
time lag
the medial SO detects frequencies best
< 3 KHz
signals from the ipsilateral side are
excitatory
signals from the contralateral side are
inhibitory
Where does the medial SO receive axons from?
anterior ventral cochlear nucleus (bilateral)
What does the lateral SO detect
differences in intensity
the lateral So works best at what frequency?
> 2-3 KHz
What nuclei does the IC have
central, pericentral, external
the LL goes to what nucleus in the IC?
central
Some axons from the LL don’t make it to the ipsilateral central nucleus of the IC, where do they go?
cross to the other side via the posterior commissure of probst
the go to contralateral central nucleus of the IC or posterior nucleus of the LL
The axons from the posterior nucleus of the LL have what neurotransmitter?
GABA
Where does the central nucleus of the IC recieve axons from?
LL
Where do the axons from the central nucleus of IC go?
anterior part of MG via brachium of IC
Where does the MG send signals to?
area 41 (specific thalamic nucleus)
What are the 2 main functions of the central nucleus?
- interaural time
2. some intensity of sound
What responds to intesity of sound?
- multipolar cells
- SO lateral
- central nucleus of the IC
T or F
pericentral and external nuclei are non-specific?
T
What is the pericentral pathway?
pericentral—->area 42——>back to superior colliculus
The axons returning to the deep SC allow participation in what>?
orientation reflex
the deep SC send what tracts to participate in the orientation reflex?
tectospinal
(neck mm)
tectomesencephalic/tectopontine
(extrinsic eye mm)
what is the pathway of the external nucleus of the IC?
external nucleus of IC—–>medial MG (large)—–>area 42
Neurons of the MG respond to what?
combinations of frequency (not individual)
time intervals between frequencies (speech)
Where does the anterior MG receive from?
central nucleus of the IC
Where does the medial MG receive from?
external nucleus of IC &
SPINAL CORD AND DCNs DIRECTLY
Where does the posterior MG receive from?
pericentral nucleus
Area 41 is broken into what?
isofrequency columns
area 41 responds to
timing and frequency
What is the pathway of area 41/42?
area 41/42—–>area 22—->area 39/40——>area 44/45 (Broca’s= area 44)
T or F
Area 41 is made of slabs of cells with concurrent function.
F
alternating
The second letter in the isofrequency column refers to….
ipsillateral side (sometimes inhibitory)
The first letter in the isofrequency column refers to….
contralateral side (always excitatory)
If Broca’s area is destroyed, what happens?
you can hear and understand, but are unable to articulate anything in order to respond
Wernicke’s area is responsible for?
semantic speech
What happens if Wernicke’s is destroyed?
everything sounds like gibberish
What layer of the retina converts to electrical signal?
layer 2
What makes up the outer layer of the eye?
sclera and cornea
What makes up the middle layer of the eye?
choroid + ciliary body/mm + iris
What layer of the retina is the furthest back?
1
Where are photoreceptors found?
layer 2
What is the area in layer 2 where photoreceptors are concentrated?
macula
Where are the cell bodies for the photoreceptors found?
layer 4
Where is light focused at in the retina?
fovea
The fovea is made entirely of
cones
The center of the fovea is known as
foveola
After the light goes to layer 2, it then travels to where?
ganglion cells of layer 8
The ganglion cells of layer 8 then send to
CN II
Where does CN 2 exit the eye?
optic disk
T or F
there are photoreceptors in the optic disk.
F
Layer 1 of the retina is known as
pigment epithelium
Layer 1 function
prevents light from scattering; also stores vitamin A
Layer 2 contains ________; which are specialized endings of _________
photoreceptors; dendrites
rods detect ______
cones detect _______
rods- black and white
cones- color
T or F cones work better in low light situations.
F
Rods and cones operate on the basis of
receptive fields
T or F
As you move away from the fovea cone concentration increases.
F
What is used for peripheral vision?
rods
What is used for night vision?
rods
What pigment do rods contain?
rhodopsin
What do rods release in the abscence of light?
glutamate
T or F
Glutamate released from the rods is inhibitory.
T
What increases when in the dark?
cGMP increases causing a Na+ influx
this causes a release of glutamate turning the bipolar cell off
How is glutamate released in the dark?
tonically
What happens when light hits rods?
activates Rhodopsin——>break down cGMP—-> decrease Na+——->decrease glutamate—–>bipolar is on
Cones are described as _______cells
photopic
What do long-wavelength cones detect?
red
What do medium-wavelength cones detect?
green
What do short-wavelength cones detect?
blue
What is deuteranopia?
green-blind—–brown/gray apperance
What is Deuteranomaly?
green-defiecient——must be bright for detection
What is achromatic vision?
colorblindness
What is the ratio of rods to ganglion cells?
10:1
What is the ratio of cones to ganglion cells?
1:1
What layer mediates these connections?
layer 6
Layer 6 is made up of what cells?
horizontal/amacrine
Horizontal cells detect what?
changes between dark and light
Amacrine cells detect?
change in the change from dark to light
Ganglion cells are found in
layer 8
How many ganglion cells per side are there?
900K- 1.2 Million
Where is the optic disk located?
15 degrees nasal to the fovea
Why dont we notice this in our visual field?
Gestalt closure principle——-filling escatoma
What are the types of ganglion cells?
- M (y)
- P (x)
- W
What type of ganglion cell does not use a center surround fashion?
W
M (y) ganglion cells recieve mostly from?
rods
M (y) cells detect
movement and contrast
M (y) are large cells and only do
black/white
P (x) receive from ________and detect
cones; color
P (x) have _______ receptor fields
small
W ganglion cells have slow conduction and go to the
SC and pre-tectal nucleus
W cells respond to
general images of light/dark
T or F
Upper/Lower visual fields swap, so images are projected upside down on the retina.
T
The upper visual field projects where?
lower LG
The upper visual field loops around ________, this is called what?
the temporal lobe,
meyer’s loop
Where does the lower visual field project?
dorsal LG
How much of the visual cortex does the macular visual field occupy?
50%
Where do all visual fields project?
layer IV of area 17
Where is the primary visual cortex most concentrated?
calcarine fissure
How many layers make up the LG?
6
Which layers of the LG are magnocellular?
1 and 2
Where do layers 1 and 2 receive from, and what do they detect?
receive from M (y);
movement and contrast
What layers are parvicellular? Where do they receive from?
layers 3-6;
P (x)
What do layers 3-6 detect?
detail, color, and shape
T or F
In the LG the layers receive either ipsilateal or contralateral ganglion cells, there is an alternating pattern.
T
What is area 17 AKA?
striate cortex
What is the bright white band of axons in layer 4 of area 17 called?
band of Gennari
T or F
Receptive fields in the LG are oval shaped and stellates in layer 4 have their own receptive fields.
F
round receptive fields
The stellates in layer 4 of area 17 have this kind of receptive field.
elongated receptive fields with center-surround
T or F
There is a 1:1 ratio of LG axons to cortical cells.
F
a convergence of many LG axons to a cortical cell
Cortical receptive fields respond to ______ of light.
bars
What do these bars end up representing?
a single continuous shape by connecting the contour of the bars of light
What are the alternating pattern of contra/ipsi parts known as in area 17?
ocular dominance columns
What is the only termination point of the LG in the cortex?
layer 4 of area 17
The other layers of area 17 receive from where?
layer 4 of area 17
What is found perpindicular to the ocular dominance columns?
orientation columns
which cells have the elongated fields?
orientation columns
What are the cells of the orientation columns known as?
simple cells
Moving away from layer 4 the cells become _______
complex cells (layers 2,3,5,6)
Describe complex cells receptive fields.
A convergence of the fields from layer 4
What do complex cells lose because of the convergence of fields?
center-surround
T or F
Complex cells are orientation specific and pick up movement/direction.
T
What are blobs?
clusters of cells between the columns; primarily respond to color.
Where do blobs receive from?
LG
Do blobs have on/off capability?
no
Are blobs layer-specific?
no
T or F
Areas 18/19 are made of simple, complex, and hypercomplex cells.
F
no simple cells
How many pathways leave area 17?
2 streams of the visual cortical pathway
What are the two streams of the visual cortical pathway?
Dorsal pathway (parietal) Ventral pathway (temporal)
Where does the parietal stream terminate?
posterior parietal area (7a)
What does the dorsal stream receive signals from and what do they detect?
M (y) ganglion cells;
motion, contrast, and localization
Which stream deals with where something is and if it is moving?
dorsal
Where do signals pass through to get to the PPA?
mid-temporal area
Where does the temporal stream terminate?
inferior temporal area (37)
Where does the ventral stream receive signals and what do they deal with?
P (x) ganglion
form/shape +color/detail
What is achromotopsia?
a form of colorblindness;
trouble with interpretaion of colors; everything is gray
What is prosopagnosia?
loss of ability to recognize form (area 17)
inability to recognize people by their face/ only physical features
What are the two ocular movements for visual tracking?
saccades + smooth pursuit
What are saccades?
sudden jerking movement of the eyes
What is the purpose of saccades?
to bring objects into the fovea for focus
can do up to 700 degrees per second
What is smooth pursuit?
following a moving object
How fast does smooth pursuit track?
30 degrees a second (much slower)
Which ocular movement involves the vestibular apparatus?
smooth pursuit
What does PPRF stand for?
paramedian pontine reticular formation
What is the PPRF’s function?
horizontal gaze center
What activates the PPRF?
the SC
If the ipsilateral lateral rectus muscle contracts, what must the contra do?
relax
What happens during staring?
SNr shuts of the SC; which in turn shuts down the PPRF so no visual tracking occurs
Does the SC normally have the SC tonically inhibited?
yes, until ready to visual track something
What is the island of reil?
insula;
island of neocortical tissue formed by deep invagination of the lateral fissure
What is the external capsule?
the area between the claustrum and puatmen
The external capsule is made of?
white matter
The extreme capsule is…
the area between the claustrum and neocortex
What does the limbic system deal with?
emotional circuitry and memory
What types of memory does the limbic system deal with?
short-term, spatial, emotional
How does memory strengthen?
by repetition….strengthening of synapses
T or F
The thalamus is a major output of the limbic system?
F
hypothalamus
What are the classifications of memory?
implicit/non-declarative
explicit/declarative
Implicit/non-declarative memory is what>?
implicit awareness; the subject is not aware they are learning
What 3 classificatins fall under implicit memory?
motor
emotional
working
What is motor memory?
how you do things
Motor memory is primarily in
cerebellum
What is emotional memory?
processing and storing emotional memory, especially negative emotions
Where is emotional memory primarily achieved?
amygdala
What is working memory?
holding something in your memory until you are done with it
Where is working memory primarily achieved?
pre-frontal cortex
What is explicit/declarative memory?
verbal; you know you are learning or memorizing something
What are the categories explicit memory?
immediate (sensory)
short-term
long-term
The immediate memory lasts?
only a few seconds
Short-term memory lasts?
minutes to days
Short-term memory usually cant do more then how many items? What does it use?
7
hippocampus
Where does long-term memory take place?
neocortex
What is long-term based off?
Long-Term Potentiation
What does LTP involve?
glutamate
What principal is involved in long term memory?
Hebb;
increase synaptic strength through repetition
What is consolidation?
turning short-term into long-term…….mostly happens at night
What is spatial memory?
ability to tell where things are in space
Sense of direction is a responsibity of the
hippocampus (place cells)
Damage to the hippocampus disrupts?
loss of short-term; loss of new long-term = Alzheimer’s
How long before Alzheimer’s symptoms occur can the ____________ be damaged?
2 years
nucleus of meynert
What are ways to increase memory?
repetition
emotional component
relating
understanding
What are the two sets of studies/experiments on the limbic system?
Kluver-Bucy
Circuit of Papez
What is Kuver-Bucy?
a result of bilateral damage to the amygdala, they found a set of 5 traditional symtoms collectivly known as Kluvaert-Bucy syndrome
What are the 5 symptoms of Kluver-Bucy
- psychic blindness
- hyperactivity
- hyperorality
- hypersexuality
- emotional changes—fearful or aggressive
What is the archicortex?
3 consecutive layers of cells
neocortex=6
What is the hippocampal formation?
hippocampus + dentate gyrus + subiculum
T or F
the dentate gyrus and hippocampus both archicortices?
T
hippocampus AKA
Ammon’s Horn
How many parts make up the hippocampus?
4
How many layers of cells does the subiculum normally have?
4 or 5======not 3 or 6
What is the fornix?
tracts leaving the hippocampus/dentate gyrus
What is the alvus?
starting point of axons
What is the crus?
where the axons thicken
What is the body of the fornix?
the tapered end
Where does the pre-commissural fornix terminate?
in the septal nuclei
Where does the post-commissural fornix terminate?
MB
What are the three septal nuclei?
- Septum pellucidum
- lateral septal nucleus
- medial septal nucleus
Trace the pathway of the posterior column of the fornix.
PC of fornix—–>MB——>AD/AV/AM——->cingulate gyrus
What part of the circuit of papez did papez not discover?
the afferents of the hippocampus
The endorhinal cortex receives from where?
cingulate gyrus
pyriform cortex
The endorhinal sends to?
subiculum
then on to the hippocampus, closing the circuit
The rhinal fissure is where?
seperating the primative olfactory region from the non-olfactory region
What does the rhinal fissure mark?
the border between the neocortex and the areas medial to it…..namely the pyriform cortex
What is the parahippocampal gyrus?
mass of cortical tissue surrounding the hippocampus
What is the anterior swelling of the parahippocampal gyrus?
uncus
What is the limbic lobe?
a “C” shaped structure made up of: cingulate +parahippocampal gyrus
Where does the parahippocampal gyrus terminate?
rostrally in the uncus
T or F the entohinal cortex is part of the parahippocampal gyrus?
T`
Where does the pyriform cortex receive from?
cingulate gyrus
Where does the pyriform cortex send to?
entorhinal cortex
What does the anterior commissure connect?
one olfactory bulb to the other
T or F
Olfaction is strongly tied to emotions and memory?
T
What loop sends axons to the hippocampus to feed vision into emotional circuitry?
Meyer’s loop
In alzheimer’s disease damage begins where, and goes to where?
hippocampus
neocortex
What are accessory limbic structures? Are they considered part of the limbic system?
olfactory bulb, Pre-Frontal Cortex, parahippocampal gyrus, and nucleus acumbens
Where are negative emotions?
amygdala
Where are positive emotions?
septal nuclei and nucleus acumbens
What structures from the diencephalon are from the limbic system?
anterior thalamic nuclei
hypothalamus
What structures from the telencephalon are part of the limbic system?
hippocampus/denate?subiculum/
amygdala
septal nuclei
cingulate gyrus
What is the amygdala?
the core of the limbic system
The amygdala processes emotional memory and is chief processor of ________ _____
negative emotions
What are the three divisions of the amygdala?
CM (corticomedial)
BL (basolateral)
Ct (central)
T or F
the BL amygdala is closest to the neocortex?
F
CM amygdala
T or F
The BL amygdala is a continuation of the claustrum?
T
Where does the posterior column terminate specifically?
medial mamillary body
Where does the endorhinal cortex receive from specifically?
lateral MB
The thalamic tubercle receives from where?
hippocampus directly and indirectly from MB
What are the afferents of the amygdala?
- olfactory bulb to CM amygdala
2. pyriform cortex to BL amygdala
What are the efferents of the amygdala?
all 3 regions of the amygdala send to nucleus acumbens
each region has their own efferents
What are the efferents of the CM amygdala?
- PVN
- preoptic
- VM nuclei (hypothalamus)
- septal nuclei
What is the CM amygdala and the septal nuclei connection an example of?
negative and positive emotions being linked
Pre-optic nucleus supplies….
testosterone
VM supplies….
estrogen
also satiety center
PVNmc supplies….
oxytocin and ADH vasopressin
PVNpc supplies?
TRH & CRH
The CM amygdala coordinates…..
olfactory signal with sexual and feeding behavior
The BL amygdala sends to
- MD (thalamus)
- nucleus of Meynert
- PFC
All the efferents of the CM amygdala make up what tract?
stria terminalis
T or F
The PFC receives from the amygdala directly from the MD and indirectly by bypassing the thalamus.
F
it bypasses the thalamus in the direct pathway and indirectly signals through the MD
The BL amygdala is responsible for two things….
- interpretation of emotion
2. coordinates a mental response to the emotional situation
The central nucleus is a ______ ______ ______ which means it is always listening.
2 way street
The Ct amygdla sends to what places?
- n. tractus solitarius and parabrachialis
- motor nucleus of 5 and CN 7
- DMn of 10 and nucleus ambiguus
- lateral hypothalamus (1 way street)
- RVLM (rostral ventral lateral medulla)
What does the efferent to the n. tractus solitarius and parabrachialis influence?
blood pressure and breathing (emotional)
What does the efferent to the motor nucleus of 5 and CN 7 influence?
masseter and mm. of facial expression (emotion)
What does the efferent to the DMn of 10 and N. ambiguus influence?
digestion and excretion (emotion parasympathetic)
What does the efferent to the lateral hypothalamus influence?
symapthtic emotional influence (1-way)
What does the efferent to the RVLM influence?
sympathetic hub…..direct to lateral horn
The efferents of the BL amygdala and the Ct amygdala make up what?
Ventro-amygdalofugal pathway
What does the lateral fissure seperate?
frontal/parietal lobes from temporal lobe
What the central fissure separate?
frontal from parietal
What does the calcarine fissure separate?
nothing, deep medial surface fissure
What does the rhinal fissure separate?
inferior temporal gyrus from parahippocampal gyrus on medial side
What is the order of sulci, fissures, and gyri starting with pre-central sulcus?
- pre-central sulcus
- pre-central gyrus
- central fissure
- post-central gyrus
- post central sulcus
post-central gyrus AKA
anterior parietal lobule
What areas form the anterior parietal lobule?
3,1,2 and 43
Areas 3,1,2 AKA
primary somatosensory cortex
T or F
the map of the body in the somatosensory cortex is ipsilateral and upside down.
F
It is contralateral and upside down
What is comitted the largest areas in 3,1,2?
face and hands
lips more specifically
T or F
Area 43 is contralateral and is not upside down. (referring to body map)
F
it is bilateral and NOT upside down
What is space alotted based on?
size of area; not importance
T or F
Area 43 has a gustatory and slow pain function.
T
a small part for gustation and retroinsular for slow pain
Area 5/7 receives from
LP of thalamus
Area 41/42 (heschl) optimal frequency
800-3500 Hz
Area 17 location
upper and lower lip of the calcarine fissure
50% of Area 17 is
the representaion of the fovea
Area 18/19 surrounds area ____ and receives from
17;
pulvinar
Area 4 aka
primary motor area
area 4 location
frontal lobe
area 4 mainly for
individual muscles
area four concentration
distal extremities
T or F
Area 4 focuses more on the hand than the face as in Area 3,2,1.
T
What is the main area in area 4 concerning the face?
tongue
T or F
Area 4 is bilateral somatotopic map.
F
contralateral
What area is in front of area 4?
Area 6
T or F
Both the medial and lateral area 6 have complete somatotopic maps.
T
Area 6L is known as
pre-motor area
Area 6L controls
axial and proximal limb musculature
setting the posture of movement
pre-motor
Area 6M is known as
supplementary motor area
Area 6M function
helps to assemble a sequence of movements
intentional preparation
What is the Pathway for mm movement?
PFC——>6M (SMA)—–>area 4 and 6L——>corticospinal tract ——>laminae 9———->skeletal mm
Area 8 is for
frontal eyefield or voluntary eye movements; visual tracking
T or F
visual tracking is a voluntary movement
F
What layer of the neocortex is well developed in sensory areas?
layer 4
What layer of the neocortex is well developed in motor areas?
layer 5
Name the 6 layers of the neocortex.
- molecular layer
- external granular layer
- external pyramidal
- internal granular layer
- internal pyramidal
- multiform layer
What layer is the outer band of baillarger in?
layer 4
What layer of the neocortex contains medium and large pyramidal cells?
layer 5
What layer receives the specific thalamic nuclei?
layer 4
What layer is mostly stellate cells?
layer 4
What layer of the neocortex contains very few neurons?
layer 1
What connects layer 3 to layer 2?
corticocortico axons
corpus callosum aka
interhemispheric commisure
What does the frontooccipial longitundinal fasiculus hook up?
visual areas to PFC
What does the uncinate fasiculus hook up?
anterior temporal lobe to PFC
what are the main areas associated with the term uncommitted cortex?
Areas 5 and 7
What is Broca’s area?
Area 44 on left=motor speech
Broca’s area does what in speech?
connecting phonemes of speech
not mm. movement
What does damage to left area 44 cause?
Broca’s aphasia (difficulty with speech articulation
Area 44 on the right is used for?
spatial perception
What is Wernicke’s area?
22 main
39/40
Area 22 aka
superior temporal gyrus
area 39 aka
angular gyrus
area 40 aka
supramarginal gyrus
area 39 function
supports reading, calculations, etc
What does Wernicke’s area on the left do?
semantic speech (meaning)
What is Wernicke’s aphasia and what side being damaged to cause?
no trouble speaking, but speech makes no sense
left
What is the right side of Wernicke’s area involved in?
prosody (non-verbal aspect of speech)
What does damage to the right side of Wernicke’s area cause?
aprosodia
failure to pick up non-verbal clues of speech
What is aphasia?
inability to speak
What is apraxia?
inability to write
What is amusia?
can’t pick up music—-only noise
What is agnosia?
loss of sensory knowledge “not-knowing”
What is prosopagnosia, and what causes it?
failure to recognize people by their face;
damage to inferior temporal region (area 37 and fusiform gyrus)
What is asomatognosia and what causes it?
a failure to recognize your own body
from damage to right inferior parietal region (usually)
What is the last part of the brain to myelinate?
PFC
What layers are most well-developed in the PFC?
2 and 3
The PFC has a strong connection with what system?
limbic
What does the PFC work with?
storing-working memory and retrieving other memory
What does the orbitofrontal PFC specialize in?
motivation, socialization and emotional control
What does the dorsal PFC specialize in?
matching, decision making, and prediction (prognostication)
The left side of the brain has what characteristics?
- more blood supply
- tends to be more analytical
- sequential
- detailed
considered scientific
What are the characteristics of the right side of the brain?
- intuitive
- holistic
- parallel (many thoughts at the same time)
considered creative
T or F
In regards to ascending spinal tracts, short tracts are confined to the spinal cord.
T
interspinal/intersegmental
Long ascending spinal tracts do what?
connect the spinal cord to something above like the brain
What are the neuron bodies of the DCs?
DRGs
What does the DC/ML system carry?
2 pt touch, proprioception, pressure and also tactile vibration
T or F
The DC/ML system is the only system to relay tactile vibration.
T
Where are the destinations for the DC/ML system?
conscious-area 3,1,2
unconscious- cerebellum
Where does gracilis bring sensation from?
lower body (foot, leg, etc.) more medial
Where does cuneatus bring sensation from
from upper body (gets larger above T6)
At T1 which is larger cuneatus or gracilis?
cuneatus
After the ML decussation where is cuneatus located?
Lateral to gracilis
T or F
Fibers from the external band of baillarger originate in the ML.
T
T or F
some axons from the ML terminate in the non-specific nuclei of the CM.
T
Where do axons from gracilis terminate?
lateral VPL (lower body)
Where do axons from cuneatus terminate?
medial VPL (upper body)
Where do axons from trigeminothalamic tract terminate?
VPM (face)
What does area 3a detect?
muscle stretch
What does area 3b detect?
slow-adapting cutaneous receptors
what does area 2 detect?
joints/mm. fascia
What is a primary order neuron?
psudounipolar neuron of the DRG
The primary order neuron makes up the ______s.
DCs
What does the secondary neuron do?
Goes from DCNs to VPL
makes up ML
What does tertiary order neuron do?
goes from VPL to neocortex
What does quaternary order neuron do?
it remains in neocortex (areas 3,2,1 and 43)
What does the anterolateral ascending spinal pathway carry?
pain, temp, and crude touch
Trace the pathway of anterolateral ascending spinal pathway from impulse to lateral spnothalamic tract.
psudounipolar cell sensation——>terminate in laminae 1-3 (primarily 2)—–>most signals to lamina 5——->anterolateral movement across white commissure——->anterior lateral funiculus—–>lateral spinothalamic tract
T or F
The segment of entry in the anterolateral ascending spinal pathway is normally 3 to four segments above the beginning segment.
F
1 to 2 segments above
T or F
In the lateral spinothalamic tract the lower body is medial and upper body is lateral.
F
vice versa
T or F
lateral spinothalamic tract crosses in the cord whereas the ML crosses in the brain.
T
T or F
The spinoreticular, spinotectal, lat. spinal thalamic, spinal mesencephalic, and spinoolivary are all part of posterolateral ascending spinal pathway?.
F
anterolateral
T or F
The map systems of the ML and anterolateral ascending spinal pathway are reversed in orientation once at the thalamus.
F
indentical at thalamus
What is the procedure done when a patient is experiencing chronic severe pain?
anterolateral cordotomy
T or F
An anterolateral cordotomy will only last about 3 years.
T
What is the destination of the spinomesencephalic tract?
PAG
this tract is considered spinoreticular
What is the sensation of the neospinalthalamic tract?
1st pain and crude touch
1st pain pathway is very well localized, well tolerated, and very rapid
What is the destination of the neospinalthalamic tract?
VPLc—->Areas 3,1,2 (SS1)
What does the paleospinothalamic tract carry?
2nd pain and temp
pain is poorly localized and poorly tolerated
“suffering pain”
What is the destination of the paleospinalthalamic tract?
post. nucleus of the thalamus—->retroinsular area of area 43—–>anterior insula—–>amygdala/entorhinal—–>hippocampus
What kind of axons carry slow pain?
C
What kind of axons carry fast pain?
A delta
What tracts are involved in pain gating?
raphespinal
Trace the pain-gating pathway.
Anterolateral ascending spinal pathway—–>PAG—(descending)—–>Raphe magnus—–>raphespinal trcats—–>lamina 2
What do neurons leaving the PAG secrete?
enkephalins
Are enkephalins excitatory or inhibitory?
inhibitory
Neurons from raphe magnus terminate on lamina 2 and _____. These neurons secrete ______.
5
secrete serotonin
How does serotonin affect lamina 2?
excitatory
How does serotonin affect lamina 5?
inhibitory
What is the purpose of serotonin exciting lamina 2?
When lamina 2 is excited it will inhibit lamina 1,2,5 using endorphins.
T or F
Endorphins and Enkephalins are the body’s natural painkillers.
T
Why does putting pressure on a wound relieve pain?
The Aa and Ab that ascend the spinal cord as cuneatus and gracilis give a branch to lamina 2. The pressure excites lamina 2 and releases endorphins. endorphins shut down pain
What is referred pain?
When class B fibers from the splachnic nn. bring in pain and temp from viscera. Lamina 5 cannot distinguish between B axons and C/Ad axons. so pain can be misinterpreted
What is the most lateral tract of the spinal cord?
spinocerebeller tract.
What sensation does the spinocerebellar tract carry?
discrimination touch, light louch, pressure, proprioception
Tract the spinocerebellar tract from origin of sensation to the inferior cerebellar pedunkle.
primary stretch receptor—->DRG—–>medial lamina 7 (nucleus of clarke)——>posterior lateral funiculus—–>posterior spinocerebellar tract—–>inferior cerebellar pedunkle
Which is larger, posterior spinocerebellar tract, or ant.?
posterior
Nucleus of clarke goes from where to where?
C8-L3
What is the nucleus of clarke?
a relay for the spinocerrebellar tract.
After entering the inferior cerebellar pedunkle what happens to the spinocerebellar tract?
inferior cerebellar pedunkle—(now MOSSY FIBERS)–>cerebellar granule cells–(PARALLEL FIBERS)–>ends on purkinje cells (ipsilateral vermis and paravermis)
T or F
axons will ascend in fasiculus cuneatus below L3 until they reach a segment where a nucleus of clarke is present.
F
they ascend in fasiculus gracilis below L3
What happens above C8? (regarding spinocerebellar)
it will not descend to look for clarke.
it ascends in cuneatus until reaching the accessory cuneate nucleus in the medulla
The axons leaving the accessory cuneate nucleus then do what?
enter the cerebellum through the inferior cerebellar pedunkle
What is the tract from the accessory cuneate nucleus to the cerebellum called?
cuneocerebellar tract
What tract creates the posterior external arcuate fibers?
cuneocerebellar tract
Where is the anterior spinocerebellar tract found?
coccygeal, sacral, and lumbar region (nothing above L1)
T or F
Anterior spinocerebellar tract axons have a synapse at the n. of clarke.
F
any neuron in lamina 7 except clarke
Do Anterior spinocerebellar tract axons go to the contralateral cerebellum?
Yes, 85-90% of the time
Where do axons from the Anterior spinocerebellar tract axons enter the cerebellum?
superior cerebellar pedunkle
parvermis aka
intermediate lobe
